The method of this project is to examine the discharge of single neurons in the awake monkey's cerebellum during natural posture and movement. The aim is to discover how cerebellar discharge differs from that of other parts of the motor system, and thus what unique properties the cerebellum contributes to the synthesis of posture and movement. Experiments in the previous grant period have shown that dentate precedes motor cortex in changing activity prior to a prompt volitional movement. Experiments in the forthcoming period if granted assume that cerebellum contributes an early component in the synthesis of the "motor command". One line of experiments will compare the timing of cerebral parietal cortex and dentate nucleus durging a different task. The aim is to confirm and extend the information on timing differences in hopes of defining the sequence (and pathway) of neural events in th@ initiation of a prompt movement. A second line of experiments will record from dentate while dissociating various aspects of the movement-joints involved, pattern of muscular activity, limb displacement, and pre-movement anticipatory set. The aim is to find out whether dentate activity releates uniquely to one (or several) of these aspects and thus what it might uniquely contribute to the rest of the motor sytem in the control movement.